Chuck.



W. A. BARKER.

CHUCK.

APPLICATION FILED IuLv 29. 191s.

Patented Dec. H, 191?.

I. N, Q

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MFFFUW,

'FmFllDML-a A. BARKJEIBM 0F GHllCltGO, IlLlLllFllllS.

CHUM.

tpectueatton of Letters Patent.

Fatentetl Decm 11, 1917..

application tied July atl, 1916. eerial No. 112,092.

To all whom it may concern:

Fe it lmown 'that ll,-WnNnnr.L A. Banner, a citizen ofthe lllnitedStates, residing at Chicago, in the county of Cook and State ofllllinois, have invented certain new and useful improvements in Chucks,of which the following is a specification.

'lhis invention has reference to chucks adapted toloe used upon latlimesand the like, and relates more' particularly to the mechanism forclosing the work-engaging jaws and holding them in gripping relationwith the work.

@ne of the salient features of' this invention is, the provision ofmeans whereby .the chuck jaws may be readily opened andv closed y thesimple.y manipulation of a hand lever while the chuck is revolving atfull speed as well as while it is standing still.

Another' object of my invention is to provide simple and efficientmechanism for controlling the chuck jaws, which will simultaneously moveall of the jaws an equal distance into work-engaging position and willhrmly holdthelp in clamping relatiop with the work, and which willmultiply a small expenditure yof force exerted upon the adjustingmechanism into an extremely heavy pressure exerted upon the jaws.

To facilitate an understanding of my inf vention andan appreciation ofits attendant advanta es l have illustrated one practical and pre erredrembodiment thereof on the accompanying drawings, which shouldbeconeidered in connection with the following description. Referring tothe drawings,-

Figure 1 j illustrates a longitudinal sectional view` through. a chuckembodying my invention;

Fi 2 is a transverse sectional viewI on thellttl'e 2-2 of Fig. l;

'Fi 3 isa similar view on the line 3.-3 of Fig. 1; and Figjt is afragmentary sectional view on the line lf-t of Fig. 1.

Referring to the drawings, reference character 5 indicatesy a spind eyof a lathe or other machine upon which the hub 6 of a chuck-body,designatedv generally by reference character 7, is` threaded in theusual manner, as shown in Fig'l. lln a series of radially arrangedgrooves 8 formed-in the front face of the chuck-body are mounted a.plurality, (in. the present instance three) of' vgripping orwork-holding jaws 9, the workengaging portions 11 of which may be of anypreferred construction, those shown for -purposes of illustrationmerely, being of re- I versible step-jaw type adapted to be reversed'and adjusted to grip objects of different sizes intended to be worked.l'llhe rear face of each back portion 12 of each jaw is provided with atransversely extending groove 13 in which there is slidablydisposed apivot block 14: provided with a central bearing aperture 16 adapted toreceive the trunnion 17 of ajaw-operating lever 18. Fach lever isprovided with o positely extending pintles 19 and 21 wiiich are re`spectively journaled in bearings formed in the front wall of thechuck-body 7 and inl the back' plate 22 which is pinned, bolted orotherwise rigidly secured to the rear face of the chuck-body. rllhepintles 19 and 21 form the fulcrums for the levers 18 about which theselevers are oscillated to move the chuckjaws in and out radially of thebody, the bearing blocks le, which are slidable transversely of thejaws, being provided for the purpose of converting the arcuate movementof the trunnion 17 into a rightr line movement of. the chuck-jaws.

'Upon the hub 6 of the chuck-body there is I sleeved or rotatablymounted a member 23 which is adapted to simultaneously actuate all ofthe levers 18 to force the chuck-jaws.

into closing position.' This member .is provided on lts periphery withthree depressions 24: arranged so that they will simul taneously receivethe anti-friction rollers 25 mounted upon the inturnedextremities 26 ofthe long arms of the levers 18, as 'clearly shown in Fig. 3.Counterclockwise frein each ofy these depressions 24 the member 2,3 isshaped to provide an elongated cam surface 2 which, when the member 23is ,par tially rotated in a clockwise direction relatively to the hub 6of the chuck-body, viewing Fig. 3, swings the long arms of the levers 18outwardly, thereby forcing the short arms inwardly to move the Vjawsinto workengaging position. llt yshould bei'ebserved that upon initialmovement of the member 23 the levers 18 will be moved relatively rapidlyas the depressions 21 travel from i ber 23 intoa very powerful grippingforce may ljaws to open exerted by the jaws upon the object or materialto be held. .The parts are so proportionedthat thecombined weight of thejaws and the short arms of the levers when multiplied by the length ofthe short arms is substantially equal to the combined weight of the longarms of the levers and the rollers 25 when multiplied by the effectivelength of the long arms, so that the jaws and the levers are practicallybalanced and are therefore affected but little, if any, by centrifugalforce when the chuck is in operation. For the purpose, however, ofinsuring' the opening of the jaws when the cam member 23 is moved toopening position as shown in Fig. 3, I provide each lever 1S with asocket 28 in which is seated a light coiled expansion spring 29 abuttingat its oute'r end against lthe surrounding wall of the chuck body, sothat the expansive force of these springs will urge the rollers 25 into7continuous engagement with the periphery of the cam member 23 therebycausing the as the cam member is moved to opening position. j. j

Any suitable mechanism maybe employed -for causing the cam Vmember 23 torotate with the chuck body and to be partially ro.- tated relatively tothe chuck-body to close or open the chuck-jaws when the chuck is'rotated. I have, for purposes of illustration, showxf ,on the drawingsone practical and preferred mechanism for accomplishing ferential wall35 and this result. Referring now to Figs. 1 and 2, it will be observedthat the depressions 24 and cam surfaces 27 are formed at the rear endofthe member 23 while the front end which projects longitudinally beyondthe back plate v22 of therotating chuck-body is provided withygearf'teeth 31. A gear 32 equal in peripheral circumference to thetoothed portion of the member 23, and also provided with circumferentialteeth 33 corresponding innumber with the teeth 31, is rigidly secured bya key34 or other suitable means to the outer end of the chuckhub 6 so asto rotate therewith.

A stationary casing comprising a circumferential wall 35, a rear wall36, and a front wall 37 in the' form `of a plate rigidly secured to theforward edge of the circumj having a forwardly projecting fiange 38loosely fittin within the back plate 22 of the chuck-bo y, is fixedlysecured to .the machine frame just rearwardly of the chuckbody so as tohouse the gears 31 and 32, as shown 'in Fig. 1. An

annular clamping nut orrin 39 may be threaded onto the rear end of t echuck-hub 6 to prevent accidental escape'of the key 34 'and to assistin.,unit1ng the parts and steadyy in the construction.

ithin the stationary casing at the junc- 'tu'refof the walls 35 and 36 Ihave fixedly secured, by means of screws 41, an internal ends of the inggear 32 and y gear 42, and laterally adjacent to said gear within thecasing is mounted an internal gear 43 of equal internal diameter andprovided with an equal number of gear teeth. A handle 44 extendingthrough a slot 45 in the circumferential wall 35 ofthe casing is fixedlysecured by bolts 46 to the internal gear 43 which, by means of thishandle, may be partially rotated within thecasing within the limitsdefined by the ends 47 and 48 of the slot 45. An annular ring 49 isloosely sleeved upon the hub 6 between the opposed gears 23 and 32, asshown in Fig. 1, and this ring carries on opposite faces a plurality ofpairs of pinions through which motion is transmitted from the gear 32 tothe gear 23.

eferring to Figs. 1 and 2, it will* be observed that the ring 49 carriesa plurality cf bearing or stud bolts 51, four being shown in the presentinstance, upon the rear ends of which are mounted pinions 52 meshingwith both the gear 32 and the internal gear 42. At their forward ends,projecting through the ring 49, these bolts are threaded vinto bushings53 upon which are rotatably 4mounted similar pinions 54, each meshingwith the teeth 31 of the member 23 and with the adjustable internal gear43.

Assuming now that the chuck is rotating, the gear 32 will be rotatedwith the hub 6 of the chuck and by reason of the intermeshing relationof the pinions 52 with the rotatthe stationary internal gear 42 the ring49 will be rotated in thc same direction as the chuck but at a slowerspeed. As-the ring rotates, carrying with it the pinions 54, each ofwhich meshes with the gear teeth 31 and the internal gear 43 whichnormally is stationary` similarly vto the gear 42, the member 23 will berotated in the same direction as the chuck and at the same speed. Sincethe jaw-operating levers 18 are carried by the chuck body and the member23 is rotating in the same direction and at the same speed as thechuck-body it will be manifest that no relative movement between themember 23 and the levers takes place, consequently the jaws will remainstationary relatively to the chuck-body. Assuming that the parts are inthe position shown in the drawlngs, with the chuck-jaws open and thechuck rotating in a clockwise direction, viewing Fig. 3, and acounterclockwise diw rection, viewing Fig. 2, should it be desirable toclose the jaws, the handle 44 is swung by the operator in a clockwisedirect-ion, viewing Fig. 2, carrying with it the movable internal gear43 which, acting through the pinions 54will impart an additional partialrotation to the member 23 relatively to the chuck body and in the samedirection that the body is rotating, with the result that the member 23will travelrelatively to the chucksbody in a clockwise direction,viewing Fig. 3, to move the cam surfaces 27 beneath the rollers 25 andthereby, through the levers 18, force the jaws into closing positionagainst the work in the chuck. When he jaws have been tightly closedagainst the work by this movement of the handle 44 they will remainlocked in closed position by the cam member 23 which continues to rotate with the chuck-body, there being` no tendency toward relativemovement of this member with respect to the chuck-body by reason of thefact that the cam surfaces 27 have a very slow rise and the rolle-rspress against the cam surfaces at substantially right angles to thesesurfaces at the point of contact. It will thus be manifest that thechuck-jaws can be closed by a simple manipulation of the handle 44irrespective of the speed at which the chuck may be rotating. When it isdesired to open the jaws the handle 44 is swung in the oppositedirection thereby imparting` a reverse movement to the member 23relatively to the chuck-body so as to permit the jaws to open under theinfluence of the coil springs 29.

It is believed that my invention and its mode of operation should bereadily understood from the foregoing without further description but itshould also be obvious that the details of construction illustrated anddescribed are capable of wide modification and variation within thepurview of the invention as defined by the following claims.

I claim:

l. In a chuck, the combination of a rotatable chuck body, jaws movableradially therein, levers pivoted on said chuck body and connected tosaid jaws, means concentric with said body and normally rotating at thesame speed and in the same direction with the latter for actuating saidlevers, and means for rotating said leveractuating means relatively tosaid body while the latter is rotating, to effect actuation of saidlevers.

2. I n a chuck, the combination of a rotatable chuck body, jaws movableradially therein, levers pivoted on said chuck body and connected tosaid jaws, cam means sleeved upon the hub of said body and engaging saidlevers, means normally effecting rotation ofsaid cam means at the samespeed and in the same direction with said body, and manually operablemeans for increasing or diminishing the speed of rotation of said cammeans relatively to the speed of rotation of said body whereby toaetuate said levers.

3. In a chuck, the combination of a rotatable chuck body, jaws movableradially therein, levers pivoted on said chuck body and connected tosaid jaws, cam means sleeved upon the hub of said body and engaging saidlevers, a planetary gear transmission intermediate said hub and said cammeans normally effecting rotation of the latter in the same directionand at the same speed with the latter, and manually operable meansacting through said planetary gear transmission to increase or diminishthe Speed of rotation of said cani means rela tively to the speed ofrotation of said body whereby to actuate said levers.

4. In a chuck, the combination of a rota table chuck body, jaws movableradially therein, levers pivoted on said chuck body and connected tosaid jaws, a sleeve rotatably mounted on the hub of said body and formedwith a plurality of cam surfaces corresponding in number to said leversand each engaging one end of one of said levers, each of said caminclines having an abrupt rise at its forward end and diminishing` ininclination to approximately zero at its rear end, means normallyeffecting rotation of said sleeve at the same speed and in the samedirection with said body, and manually operable means for increasing ordiminishing the speed of rotation of said sleeve relatively to the speedof rotation of said body.

5. In a chuck, the combination of a body, a plurality of jaws mountedfor radial movement thereon, levers mounted upon axes par allel with theaxis of rotation of said body Vhaving their short arms connected wthsaid jaws, and means disposed within the chuckbody in position to actupon the long arms of said levers to force the jaws into closedposition, the combined weight of the jaws and the short arms of thelevers multiplied by the effective length of said short arms beingapproximately equal to the weight of the long arms of the leversmultiplied by the effective length of said long arms, whereby said jawsand levers are substantially bal` anced within the chuck body.

WENDELL A.. BAKKER.

